acquired immunity
Production of antibodies and lymphocytes after exposure to an antigen.
adenoids
Mass of lymphatic tissue in the nasopharynx.
antibody
Protein produced by B cell in lymphocytes to destroy antigens.
antigen
Substance that the body recognizes as foreign; evokes an immune response. Most antigens are proteins or protein fragments found on the surface of bacteria, viruses, or organ transplant tissue cells.
axillary nodes
Lymph nodes in the armpit (underarm)
B cell (B lymphocyte)
Lymphocyte that originates in the bone marrow and transforms into a plasma cell to secrete antibodies. The B refers to the bursa of Fabricius, an organ in birds in which B cell differentiation and growth were first noted to occur.
cervical nodes
Lymph nodes in the neck region.
complement system
Proteins in the blood that help antibodies and T cells kill their target.
cytokines
Proteins that aid and regulate the immune response. Examples are interferons and interleukins.
cytotoxic T cell
T lymphocyte that directly kills foreign cells (CD8+ cell or T8 cell)
dendritic cell
Specialized macrophage that digests foreign cells and helps B and T cells to mark antigens for destruction.
helper T cell
Lymphocyte that aids B cells and cytotoxic T cells in recognizing antigens and stimulating antibody production; also called CD4+ cell or T4 cell.
immunity
Body's ability to resist foreign organisms and toxins. This includes natural immunity and acquired immunity.
immunoglobulins
Antibodies (gamma globulins) such as IgA, IgE, IgG, IgM, and IgD that are secreted by plasma cells in response to the presence of an antigen.
immunotherapy
Use of immune cells, and antibodies, or vaccines to treat or prevent disease.
inguinal nodes
Lymph nodes in the groin area.
interferons
Proteins (cytokines) secreted by T cells to aid and regulate the immune response.
interleukins
Proteins (cytokines) that stimulate the growth of B and T lymphocytes
interstitial fluid
Fluid in the spaces between cells. This fluid becomes lymph when it enters lymph capillaries.
lymph
Thin, watery fluid found within lymphatic vessels and collected from tissues throughout the body.
lymph capillaries
Tiniest lymphatic vessels.
lymphoid organs
Lymph nodes, spleen, and thymus gland.
lymph node
A collection of stationary solid lymphatic tissue along lymph vessels.
lymph vessel
Carrier of lymph throughout the body; lymphatic vessels empty lymph into veins in the upper part of the chest.
macrophage
Large phagocyte found in lymph nodes and other tissues of the body.
mediastinal nodes
Lymph nodes in the area between the lungs in the thoracic (chest) cavity.
monoclonal antibody
Antibody produced in a laboratory to attack antigens and to destroy cells. It is useful in immunotherapy.
natural immunity
Protection that an individual inherits to fight infection.
plasma cell
Lymphocyte that produces and secretes antibodies. It originates from B lymphocytes.
right lymphatic duct
Large lymphatic vessel in the chest that receives lymph from the upper right part of the body.
spleen
Organ near the stomach that produces, stores, and eliminates blood cells.
suppressor T cell
Lymphocyte that inhibits that activity of B and T lymphocytes. Also called a Treg (regulatory T cell).
T cell (T lymphocyte)
Lymphocyte that originates in the bone marrow but matures in the thymus gland; it acts directly on antigens to destroy them or produce chemicals (cytokines) such as interferons and interleukins that are toxic to antigens.
tolerance
The ability of T lymphocytes to recognize and accept the body's own antigens as "self" or friendly. Once tolerance is established, the immune system will not react against the body.
thoracic duct
Large lymphatic vessel in the chest that receives lymph from below the diaphragm and from the left side of the body above the diaphragm; it empties the lymph into veins in the upper chest.
thymus gland
Organ in the mediastinum that conditions T lymphocytes to react to foreign cells and aids in the immune response.
tonsils
Mass of lymphatic tissue in the back of the oropharynx.
toxin
Poison; a protein produced by certain bacteria, animals, or plants.
vaccination
Exposure of an individual to a foreign protein (antigen) that provokes an immune response. The response will destroy any cell that possesses the antigen on its surface and will protect against infection.
vaccine
Weakened or killed microorganisms, toxins, or other proteins given to induce immunity to infection or disease.
immun/o
protection
lymph/o
lymph
lymphaden/o
lymph node (gland)
splen/o
spleen
thym/o
thymus gland
tox/o
poison
ana-
again, anew
inter-
between
-phylaxis
protection
severe combined immunodeficiency disease (SCID)
Infants are born with a deficiency of B cells and T cells, resulting in a lack of immunity. The thymus is small, and children have little or no protection against infection.
acquired immunodeficiency syndrome (AIDS)
Group of clinical signs and symptoms associated with a suppression of the immune system and marked by opportunistic infections, secondary neoplasms, and neurologic problems. AIDS is caused by HIV.
candidiasis
Yeast-like fungus (Candida), normall present in the mouth, skin, intestinal tract, and vagina, overgrows, causing infection of the mouth (thrush), respiratory tract, and skin.
cryptococcal infection (Crypto)
Yeast-like fungus (Cryptococcus) causes lung, brain, and blood infections. Pathogen is found in pigeon droppings and nesting places, air, water and soil.
cryptosporidiosis
Parasitic infection of the gastrointestinal tract and brain and spinal cord. The pathogen, Cryptosporidium, is a one-celled organism commonly found in farm animals.
cytomegalovirus (CMV) infection
Virus causes enteritis (inflammation of the intestinal tract) and retinitis (inflammation of the retina at the back of the eye). Found in saliva, semen, cervical secretions, urine, feces, blood and breast milk, but usually causes disease only when the imm
herpes simplex
Viral infection causes small blisters on the skin of the lips or nose or on the genitals. Herpes simplex virus also can cause encephalitis.
histoplasmosis (Histo)
Fungal infection caused by inhalation of dust contaminated with Histoplasma capsulatum; causes fever, chills, and lung infection. Pathogen is found in bird and bat droppings.
Mycobacterium avium-intracellulare (MAI) complex infection
Bacterial disease manifesting with fever, malaise, night sweats, anorexia, diarrhea, weight loss, and lung and blood infections.
Pneumocystis pneumonia (PCP)
One-celled organism (P. jiroveci) causes lung infection, with fever, cough, and chest pain. Pathogen is found in air, water, and soil and is carried by animals. Infection is treated with trimethoprim-sulfamethoxazole (Bactrim), a combination of antibiotic
toxoplasmosis (Toxo)
Parasitic infection involving the central nervous system (CNS) and causing fever, chills, visual disturbances, confusion, hemiparesis (slight paralysis in half of the body), and seizures. Pathogen (Toxoplasma) is acquired by eating uncooked lamb or pork,
tuberculosis (TB)
Bacterial disease (caused by Mycobacterium tuberculosis) involving the lungs, brain, and other organs. Signs and symptoms are fever, cough, loss of weight, anorexia, and blood in sputum.
allergy
Abnormal hypersensitivity acquired by exposure to an antigen.
lymphoma
Malignant tumor of lymph nodes and lymph tissues.
multiple myeloma
Malignant tumor of bone marrow cells
thymoma
Malignant tumor of the thymus gland.
allergen
Substance capable of causing a specific hypersensitivity reaction in the body; a type of antigen.
anaphylaxis
Exaggerated or unusual hypersensitivity to foreign protein or other substance.
atopy
Hypersensitive or allergic state involving an inherited predisposition.
CD4+ cells
Helper T cells that carry the CD4 protein antigen on their surface. HIV binds to CD4 and infects and kills T cells bearing this protein. AIDS patients have an inadequate number of CD4+ cells.
Hodgkin disease
Malignant tumor of lymphoid tissue in spleen and lymph nodes; Reed-Sternberg cell often is found on microscopic analysis.
human immunodeficiency virus (HIV)
Virus (retrovirus) that causes AIDS.
Kaposi sarcoma
Malignant lesion associated with AIDS; arises from the lining of capillaries and appears as red, purple, brown, or black skin nodules.
non-Hodgkin lymphomas
Group of malignant tumors involving lymphoid tissue. Examples are follicular lymphoma and large cell lymphoma.
opportunistic infections
Infectious diseases associated with AIDS; they occur because HIV infection lowers the body's resistance and allows infection by bacteria and parasites that normally are easily contained.
protease inhibitor
Drug that treats AIDS by blocking the production of a protease, a proteolytic enzyme that helps create new viral pieces for HIV.
reverse transcriptase inhibitor (RTI)
Drug that treats AIDS by blocking reverse transcriptase, an enzyme needed to make copies of HIV.
wasting syndrome
Weight loss, decrease in muscular strength, appetite, and mental activity; associated with AIDS.
CD4+ cell count
Measures the number of CD4+ T cells (helper T cells) in the bloodstream of patients with AIDS.
ELISA
Screening test to detect anti-HIV antibodies in the bloodstream. (enzyme-linked immunosorbent assay).
immunoelectrophoresis
Test that separates immunoglobulins (IgM, IgG, IgE, IgA, IgD).
viral load test
Measurement of the amount of AIDS virus (HIV) in the bloodstream.
computed tomography (CT) scan
X-ray imaging produces cross-sectional and other views of anatomic structures.